Lubricating oil compositions containing acylated polyamine salts



United States Patent 2,862,883 LUBRICATING 01L COMPOSITIONS CONTAININGACYLATED POLYAMINE SALTS John Hughes, Ellesmere Port, Chester, andPhilip James Garner, Hooton, Wirral, England, assignors to ShellDevelopment Company, New York, N. Y., a corporation of Delaware NoDrawing. Application January 11, 1957 Serial No. 633,518 Claimspriority, application Great Britain January 18, 1956 7 Claims. (Cl.252-334) This invention relates to improved lubricating oilcompositions, and more particularly to highly detergent lubricating oilswhich possess improved spreading pressure properties.

Until recently, lubricating oil detergents or dispersants were generallypolyvalent metal salts or soaps of organic carboxylic or sulfonic acidssuch as organic naphthenic or organic sulfonic acids. Detergents of thistype are relatively ineffective at extremely low or extremely hightemperatures and do not improve the spreading pressure of lubricatingoils on various surfaces.

It has now been discovered that the detergent properties of lubricatingoils over a wide temperature range as well as the spreading pressure onvarious solid surfaces e. g. metals, can be greatly improved byincorporation in the oil of a small amount of certain oil-solublepartially acylated aliphatic polyamine salts of aromatic acidiccompounds, particularly of one which is a sulfonic acid, carboxylic acidor phenolic compound, such as a petroleum or a synthetic alkarylsulfonic acid, an alkyl salicylic acid, a simple alkylphenol or apoly(alkylphenol). These acylated polyamine salts are, thus, amidoalkylene amine salts of the aromatic acid. The N-acyl radical formingthe amido group(s) is an acyl radical of a carboxylic acid, preferablyan aliphatic (cyclic or acyclic) monocarboxylic acid.

The polyamines from which the amido alkylene amines are derivable arealiphatic polyamines which may be simple polyaminoalkanes, such as thediaminoalkanes, 1,2-diaminoethane, 1,2- or 1,3-diaminopropane, 1,2-,1,3- or 1,4-diaminobutane, 2,3-diaminohexane, poly(alkylenediamines),such as diethylene triamine, triethylene tetramine, tetraethylenepentamine, dipropylene triamine, tripropylene tetramine,N-alkyldiaminoalkanes such as N- butyl ethylene diamine, diaminoalkylethers, including thioethers, such as di-(2-aminoethyl)sulphide, and thelike.

The N-acyl group (s) (Elia of the amido group(s) corresponds to acylradicals of any carboxylic acid, such as benzoic acid, salicylic acid,octyl salicylic acid, naphthoic acid, naphthenic acids, caproic acid,lauric acid, stearic acid or palmitic acid. Particularly suitable arethe naphthenic acids obtained as by-products in the refining ofpetroleum fractions, such as kerosene, gas oil and lubricating oil;

The following are typical specific partially acylated aliphatic diorpoly-amines which, in the form of their oil-soluble salts with aromaticacids, particularly with the specific aromatic acids mentioned above,may be used as lubricating oil additives in accordance with thisinvention: the mononaphthenic amide of 1,2-diaminoethane, of1,2-diaminopropane, of diethylene triamine or of triethylene tetramine,the monolauric amide of tetraethylene pentamine, and the monostearicamide of hexamethylene diamine or of 2,3-diaminohexane.

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The partially acylated aliphatic dior poly-amines may be prepared by theaction of a corboxylic acid or a halide, nitrile or ester thereof on thedior poly-amine by methods which are well-known in the art. Thepreferred method involves mixing equimolecular parts of acid and amineand heating in an autoclave at a temperature of from about 170 C. toabout 200 C. for about 5 to 8 hours. The crude reaction mixtures soobtained may be used as such to form the salts which are used inaccordance with the present invention. These salts may be prepared byany of the methods known for preparing salts of amines. For instance asolution of the partially acylated dior poly-amine in a solvent such aspetroleum spirit, may be mixed with a stoichiometric proportion of theacid, preferably dissolved in the same solvent. Alternatively, the saltcan be prepared by metathesis of, for example, the hydrochloride orsulphate of the partially acylated dior poly-amine with the alkali metalsalt of the acid in a solvent which facilitates the removal of theinorganic salt produced.

The aromatic acidic compounds from which the oilsoluble acylatedpolyamine salts are derived include aromatic sulfonic acids such as thenonyl or dodecyl benzene sulphonic acids, di-isopropyl naphthalenesulphonic acid, butyl phenol sulphonic acid and sulphonic acids derivedfrom aromatic fractions from petroleum oils or the alkylation productsof such fractions; alkyl salicylic acids such as octadecyl anddiisopropyl salicylic acids and mixtures of alkylated salicylic acids inwhich the alkyl groups contain 8 to 18 carbon atoms; or phenols such asoctyl and dodecyl phenols, the butyl and amyl naphthols or polyphenolsobtained by condensing simple phenols at open positions ortho and/orpara to the phenolic hydroxy group through alkylidene (methylene)radicals such as are obtained by condensing alkylated phenols e. g.p-octylphenol with formaldehyde or acetaldehyde. Particularly usefulproducts of this type range in molecular weight from 500 to about 1100.

The preparation of the acylated polyamines (amidoamines) and their saltsis illustrated in the following examples. In these examples, parts byweight (referred to hereinafter as p. b. W.) and parts by volume(referred to hereinafter as p. b. v.) bear the same relation to eachother as the kilogram to the litre.

The naphthenic acid used to prepare the following naphthenamides was amixture of acids obtained by distilling a petroleum lubricating oilfraction over caustic soda and recovering the naphthenic acids from theresidue containing sodium naphthenates. The acid had an acid value of170 milligrams of potassium hydroxide per gram, corresponding to anaverage molecular weight of about 4.35, the naphthenic acids beingessentially monocarboxylic acids.

Example I N (2 aminoethyl)naphthenamide was prepared by heatingnaphthenic acids (1.5 p. b. w.) with ethylene diamine (1.09 p. b. w.),in a mol ratio of l to 4, respectively, at reflux for 160 hours, at theend of which time the reaction was about percent complete. Most of theexcess ethylene diamine was then removed under reduced pressure. Thecrude material (about 2 p. b. w.) was dissolved in 50 percent aqueousisopropyl alcohol (3 p. b. v.) and neutralized to bromophenol blue withconcentrated hydrochloric acid (ca 1.5 p. b. v.). Petroleum spirit (1 p.b. v.) and Water (1. p. b. v.) were added, whereupon two layers formedand the aqueous lower ethylene diamrnonium chloride layer was removed.One further wash with water (1 p. b. v.) was given, after .which water(6 p..v. b.), isopropyl alcohol (3 p. b. v.) and petroleum spirit (1 pb.v.) were added. The reaction mixture separated to give a yellowpetroleum spirit top layer, and a bottom layer containingN-(2-aminoethyl)naphthenamide hydrochloride (2 p. b. -w.) dissolved inaqueous isopropyl alcohol (13 p. b. v.). The bottom layer was washed sixtimes with petroleum spirit (1 p. b. v. portions) and the combinedpetroleum spirit extracts were back extracted with 35 percent aqueousisopropyl alcohol (1 p. b. v.). The combined aqueous alcoholic layerswere made alkaline to phenolphthalein with 40 percent sodium hydroxidesolution and petroleum spirit (5 p. b. v.) was added. A brown petroleumspirit layer separated, the aqueous layer was run oil? and washed oncewith petroleum spirit (0.5 p. b. v.). The combined petroleum spiritsolutions were washed three times with water (0.1 p. b. v. portions) andthesolvent removed.

Approximately 1.1 p. b. w. (62 percent based on acid) of product wasobtained. It has a neutralization value of 148 mg. KOH/g. (theory 151mg. KOH/g. for the monoamidoamine).

Example II N-(Z-aminoethyl) naphthenamide was prepared by heatingnaphthenic acid (331 p. b. W.) and commercial grade ethylene diamine(279 p. b. w.) containing 14 percent by weight of water, at 180 C. undera pressure of about 7 atmospheres for 6 hours. The reaction mixture wasstripped of excess ethylene diamine under reduced pressure and worked upas described under Example I. The yield of N-(Z-aminoethyl)naphthenamide was 252 p. b. w. (67.5 percent of theory).The product had a neutralization value equivalent to 152 milligrams ofpotassium hydroxide per gram (theory 151 mg. KOH/g.).

The amount of imidazoline derivative formed during the reaction bycyclization of the N-aminoethyl naphthenamide was about 1.5 percent byweight. The neutralization value agreed with that required theoreticallyand the color of the product was good. Longer reaction times and higherreaction temperatures tended to increase the proportion of imidazolinederivative formed.

The presence of water in the initial reaction mixture had no adverseeffect on the reaction as similar yields of the naphthenamide wereobtained using anhydrous ethylene diamine.

Example III N-(3-aminopropyl)naphthenamide was prepared by heating1,3-diaminopropane (29.6 p. b. w.) and naphthenic acid (33.1 p. b. w.)at 150 C. for 160 hours at atmospheric pressure. The reaction mixturewas worked up as described in Example I to,give 22 p. b. w. ofnaphthenamide having a neutralization value equivalent to 141 milligramsof potassium hydroxide per gram (theory 141 mg. KOH/g.) and nitrogencontent 7.9 percent (theory 7.2 percent).

N-(S-aminooctyl)naphthenamide was prepared in a similar manner.

Example IV 1,2-diaminopropane (29.6 p. b. w.) and naphthenic acid (33.1p. b. w.) were heated together at 150 C. for 160 hours, and the reactionmixture worked up in the manner described in Example I to give 17.7 p.b. w. of naphthenamide having a neutralization value equivalent to 121milligrams of potassium hydroxide per gram (theory 145 mg. KOH/g.) andnitrogen content 7.2 percent (theory 7.2 percent).

Example V Naphthenic acid (13.8 p. b. w.) and diethylene triamine (9.1p. b. w.) were heated together at 180 -C. for 6 hours at atmosphericpressure and the reaction mixture was worked up as described in ExampleI to give a 69 percent yield of N-(5-amino-3-azapentyl)naphthenamide.

The preparation of some of the naphthenamide salts of the invention isdescribed in the following examples.

4 Example VI In this example is described the preparation of the Kerexsulphonates of the above amino alkyl naphthenamides. Kerex, for keroseneextract, is an aromatic extract of kerosene obtained by treatingkerosene with liquid sulphur dioxide in the Edeleanu process. It has anA. S. T. M. boiling range of 165 to 270 C. and contains approximately 70percent by weight of aromatic hydrocarbons.

To prepare Kerex sulphonic acid, 20 percent fuming sulphuric acid (150p. b. v.) was added to the full Kerex fraction (368 p. b. w.) cooled inice water, the reaction temperature being maintained at 25 to 30 C. Thereaction mixture was poured into water (600 p. b. v.) and unreactedKerex (49 percent by weight) was separated. The aqueous lower layer wasneutralized with aqueous sodium hydroxide solution containing 25 percentby weight of the alkali and the volume adjusted to 2,000 p. b. v. at 25C. Under these conditions, no crystallization of sodium salt occurredand the solution contained 13.45 percent by weight of sodium Kerexsulphonate.

This solution was used as such or the sodium Kerex sulphonate wasextracted from it by means of normal butanol. The butanol extract wasdried azeotropically, filtered to remove inorganic salts and evaporatedunder reduced pressure, the residual salt being washed with ether anddried. The solid sodium Kerex sulphonate contained 10 percent by weightof sodium and was obtained in 70 percent yield based on the Kerexconsumed or 39 percent yield on total Kerex used.

(a) N-(Z-aminoethyl)naphthenamide Kerexsulphonate.-N-(Z-aminoethyl)naphthenamide (100 p. b. w.) in aqueousalcoholic solution was neutralized with concentrated hydrochloric acidusing methyl red as indicator and then shaken with 430.6 p. b. w. of theabove 13.45 percent by weight aqueous sodium Kerex sulphonate solution.The mixture was extracted with petroleum spirit and the extract dried byazeotropic distillation, filtered to remove precipitated sodium chlorideand evaporated to dryness.

The residual salt (146 p. b. w.; 96 percent yield) had a nitrogencontent of 5.2 percent (theory 4.9 percent).

(b) N-(aminopropyl)naphthenamide Kerex sulphonate.This salt was preparedin percent yield by a method similar to that described under (a) abovefrom N-(aminopropyl)naphthenamide hydrochloride (derived from1:2-diaminopropane) and sodium Kerex sulphonate in aqueous alcohol, andextracting the amine Kerex sulphonate with benzene. The product had anitrogen content of 4.6 percent (theory 4.5 percent).

(0) N-(3-aminopropyl)naphthenamide Kerex sulphonate containing 4.8percent nitrogen (theory 4.5 percent) and N-(8-aminooctyl)naphthenamideKerex sulphonate containing 4.8 percent nitrogen (theory 4.0 percent)were prepared by the procedure similar to that described under (a). Thelatter product contained some 1:8-diaminooctane as impurity.

(d) Kerex sulphonates of N-(5-amino-3-azapentyl) naphthenamide. By theprocedure described in (a) there were prepared the mono Kerex sulphonate(found, N, 6.4, S, 5.2 percent; theory, N, 6.5, S, 5.0 percent) and thediKerex sulphonate (found, N, 5.1, S, 7.4 percent; theory N, 4.8, S, 7.3percent) of N-(5-amino-3-azapentyl)naphthenamide by reacting oneequivalent of the amine hydrochloride with one and two equivalents,respectively, of sodium Kerex sulphonate.

Example VII In this example is described the preparation of the alkylKerex sulphonate of N-(Z-aminoethyDnaphthenamide. The sodium alkyl Kerexsulphonate used for this purpose was prepared as follows:

A Kerex fraction boiling at approximately 114 C. at 20 millimeterspressure was used. It had a molecular weight of 157 and contained 70percent by weight of aromatics. The alkylation was effected by addingpowdered anhydrous aluminum chloride (3.3 p. b. w.) to the Kerexfraction (278.5 p. b. W.) at 25 C. and adding gradually to the stirredmixture 44.8 p. b. w. of a cracked petroleum fraction consisting mainlyof straight chain olefins containing 8 carbon atoms in the molecule andwhich had a bromine number of 119 (theory for C H 143). These olefinshad been obtained by extracting a C -fraction of cracked petroleum withurea to remove branched olefins. When addition of the olefin wascomplete, a further 13 p. b. W. of aluminum chloride were added. Thestirrer was stopped after 6 hours and the mixture left for a furtherhours after Which the liquid fraction was decanted from the sludgeformed and stirred with 10 percent by weight of an aqueous alkalisolution containing 20 percent by weight of sodium hydroxide.

The hydrocarbon layer was distilled giving 124 p. b. W. of a fractionboiling at 96 to 122 C. at 18 millimeters pressure, molecular weight166, which was mainly unreacted Kerex, and 758 p. b. w. of a secondfraction boilmg at 118 to 144 C. and 0.5 millimeter pressure, molecularweight 232 which was the desired alkyl Kerex. There was a small residue.

The C -alkyl Kerex (70 p. b. w.) was reacted with 100 percent sulphuricacid (70 p. b. w.) at 30 to 35 C. for 1 hour. The reaction mixture waspoured into ice water and then warmed to 70 to 80 C. to break theemulsion which formed. The lower aqueous layer containing very littlesulphonate was discarded. 95 percent ethanol (90 p. b. v.) was thenadded and the upper layer of unreacted hydrocarbon which separated onstanding was removed.

The aqueous alcoholic layer was neutralized at 60 C. with solid sodiumhydroxide (10 p. b. w.), using phenolphthalein as indicator, and 95percent ethanol (4 p. b. v. added. The cooled solution was filtered frominorganic salts and the solvent removed by distillation under reducedpressure. An 84 percent yield of sodium C -alkyl Kerex sulphonate (81 p.b. w.) was obtained containing 96 percent by weight of the salt.

N-(2-aminoethyl)naphthenarnide alkyl Kerex sulphonate was prepared fromthe above sodium C -alkyl Kerex sulphonate (34 p. b. w.) and thehydrochloride from N (2-aminoethyl)naphthenamide (31.1 p. b. w.) inaqueous alcoholic solution. The product was extracted with and desaltedin benzene and yielded N-(2-amin0- ethyl)naphthenamide C -alkyl Kerexsulphonate (58 p. b. w.; 96 percent yield) having a nitrogen content of4.1 (theory 4.1 percent).

Example VIII N (Z-aminoethyl)naphthenamide dodecylbenzene sulphonate wasprepared by a method similar to that described under Example VI(a) byreacting sodium dodecylbenzene sulphonate (35 p. b. w.) and thehydrochloride from N (2 aminoethyDnaphthenamide (34.2 p. b. w.) inaqueous alcohol, the desired salt being extracted with and desalted inbenzene and finally obtained by evaporation of the benzene solution(59.6 p. b. w., 90 percent theory). It had a nitrogen content of 4.0percent (theory 4.2 percent). The dodecyl benzene sulphonic acid wasobtained by sulphonating benzene which had been alkylated withpropylene-tetramer.

The N-(Z-aminoethyl)naphthenamide benzene sulphonate was prepared in asimilar manner from the naphthenamide and sodium benzene sulphonate.

Example IX N (2 aminoethyl)naphthenamide naphthasulphonate was preparedby reacting the hydrochloride from N-(2- aminoethyl)naphthenamide withsodium naphthasulphonates in aqueous isopropyl alcohol. The sodiumnaphthasulphonates used are obtained as byproducts in the refining oftechnical white oils and medicinal oils in the petroleum industry. Theyare oil-soluble salts and are available in a range of molecular weights.Normally they contain a minor proportion of oil which can be removed bywashing an aqueous alcoholic solution of the sodium naphthasulphonateswith light petroleum. Both oiled and de-oiled sodium naphthasulphonateswere used to prepare the naphthenamide sulphonates. The preparations aresummarized in the following table.

N-(Z-a-minoethyl)naphthenamide di-isopropyl salicylate was prepared bymixing a solution of di-isopropyl salicylic acid (33.6 p. b. w.) inlight petroleum (B. P. 40 to 60 C.) with a solution ofN-(2-aminoethyl)naphthenamide (56 p. :b. w.) also in light petroleum. Acurdy precipitate formed. The solvent was removed by distillationleaving 98 p. b. w. of the salicylate which had a nitrogen content of4.7 percent (theory 4.7 percent). The di-isopropyl salicylic acid usedwas obtained by carboxylating di-isopropyl phenol which had beenobtained by alkylating phenol with 2 molecular proportions of propylenein presence of anhydrous aluminum chloride.

Example XI N-(2-aminoethyl)naphthena-mide C C alkyl salicylate wasobtained in 99 percent yield by reacting equivalent proportions ofsodium C -C -alkyl salicylate and N-(Z-aminoethyl)naphthenamidehydrochloride in ethyl alcoholic solution. The sodium chlorideprecipitated was filtered off and the filtrate treated with decolorizingcharcoal, filtered and evaporated to dryness under reduced pressure. Theproduct contained 3.7 percent nitrogen (theory 3.8 percent). The alkylsalicylic acids used in this preparation were obtained by carboxylatingphenol which had been alkylated with a mixture of G to C alkenes-l inthe presence of anhydrous aluminum chloride.

The proportion of the oil-soluble salts derived from a partiallyacylated aliphatic dior poly-amine and an aromatic acid used inaccordance with this invention will vary greatly depending upon theeifectiveness of the particular salt employed and the degree ofimprovement of the properties of the base lubricating oil required.Usually, the salt will be used in a proportion of from 0.1 to 5% byweight of the base oil. More usually, the proportion used will bebetween 0.2 and 2% by weight.

The lubricating oil used in the compositions of this invention may beany natural (hydrocarbon and polar containing oils) or synthetic oil(olefin polymers, esters, ethers, etc.) having lubricating properties.Thus, it may be a mineral lubricating oil obtained from a parafiinic,naphthenic, asphaltic or mixed base crude petroleum. The viscosities ofthese mineral lubricating oils may vary over a wide range such as from40 SUS at F. to 1000 SUS at 210 F. Typical synethetic lubricating oilswhich may be used are polymerized olefins, organic esters such asdi(2-ethylhexyl)sebacate, dioctyl phthalate and trioctyl phosphate andsilicon polymers. The base lubricating oil may be a mineral lubricatingoil mixed with a synethetic lubricating oil or with a fatty oil such ascastor oil or lard oil.

A typical lubricating composition of the present invention is asolvent-refined mineral lubricating oil having a viscosity of 330seconds Redwood I at 140 F. (hereinafter called oil A), to which hasbeen added from 0.2 to 2% by weight of the N-(2-amino-ethyl)naphthenamide C14C18 alkyl salicylate described in ExampleXI. Such a composition containing 2% by weight of the additive wastested for high temperature properties in the following coking test. Ahot clean metal plate is maintained at about 200 C. and the oil undertest is allowed to run down the surface in a film at the rate of onedrop per second. This is continued for 45 minutes, the plate is cooledand washed down with petroleum ether. Applying this test to the baseoil, the plate finished up in a black coked condition but, with the oilcontaining the additive, the plate was unmarked except for a few greystreaks.

To illustrate the effect on the spreading pressure of oil A of addingvarious quantities of additive of Example XI, the spreading pressures ofoil A on steel and on water and of oil A containing varying percentagesof additive of Example XI were determined. The results are set out inthe following table.

Spreading pressure (dynes/square Cone. of additive 01 Example XI,percent w. centimeter) on- Steel Water Compositions of this inventioncan be used as engine oils, turbine oils, gear oils, cutting oils andvarious other fields of lubrication where detergency and stability areessential.

We claim as our invention:

1. A lubricating oil composition comprising a major amount of a minerallubricating oil and a minor but detergent amount of an oil-solublemono-acylated aliphatic polyamine salt of an aromatic acidic compoundwherein the acidic radical is selected from the group consisting ofphenolic hydroxy group, carboxylic acid and sulfonic acid.

2. A lubricating oil composition comprising a major amount of a minerallubricating oil and a minor, but detergent amount of an oil-solublemono-acylated aliphatic polyamine salt of an aromatic sulfonic acid.

3. A lubricating oil composition comprising a major amount of a minerallubricating oil and a minor, but detergent amount of an oil-solublemono-acylated aliphatic polyamine salt of an alkyl salicylic acid.

4. A lubricating oil composition comprising a major amount of a minerallubricating oil and a minor, but detergent amount of an oil-solublemono-acylated aliphatic polyamine salt of a phenol.

5. The composition of claim 2 wherein the salt is N-(2- aminoethyl)naphthenamide salt of dodecyl benzene sulfonic acid.

6. The composition of claim 3 wherein the salt is N-(2- aminoethyl)naphthenamide salt of C -C alkyl salicylic acid.

7. The composition of claim 4 wherein the salt is N-(2- aminoethyl)naphthenamide salt of octyl phenol-formaldehyde condensationproduct.

References Cited in the file of this patent UNITED STATES PATENTS2,336,070 Clarkson Dec. 7, 1943 2,481,585 Freeman Sept. 13, 19492,493,483 Francis et a1. Jan. 3, 1950

1. A LUBRICATING OIL COMPOSITION XCOMPRISING A MAJOR AMOUNT OF A MINERALLUBRICATING OIL AND A MINOR BUT DETERGENT AMOUNT OF AN OIL-SOLUBLEMONO-ACYLATED ALIPHATIC POLYAMINE SALT OF AN AROMATIC ACIDIC COMPOUNDWHEREIN THE ACIDIC RADICAL IS SELECTED FROM THE GROUP CONSISTING OFPHENOLIC HYDROXY GROUP, CARBOXYLIC ACID AND SULFONIC ACID.